Aero Precision makes a wide variety of AR15 Upper Receivers, and the M4E1 AR-15 16in 5.56 Mid Barrel Complete Upper Receiver with Flash Hider is an amazing option. Designed to give you the full M4 package in a lightweight, durable design, the Aero Precision M4E1 AR-15 16in 5.56 Mid Barrel Complete Upper Receiver with Flash Hider comes with everything you need to start shooting as soon as you attach it to your lower receiver. It even has a flash hider to help control muzzle flash and muzzle rise when you're shooting, making you harder to spot and keeping your shots true. The Picatinny rails and M-LOK attachment ports provide plenty of space for a rifle scope, weapon light, laser sight, foregrip, and plenty of other attachments, so you can customize the firearm easily. If you've been looking to build a new AR15, pick up the Aero Precision M4E1 AR-15 16in 5.56 Mid Barrel Complete Upper Receiver with Flash Hider today. Specifications for Aero Precision M4E1 AR-15 16in 5.56 Mid Barrel Complete Upper Receiver with Flash Hider: Manufacturer: Aero Precision Cartridge: 5.56x45mm NATO Overall Length: 26 in Barrel Length: 16 in Barrel Profile: Government Gas System Length: Mid Length Barrel Twist Rate: 1-7 Threads per Inch: 1/2x28 Handguard Type: Free-Float Muzzle Device: A2 Flash Hider Gun Model: M16, AR-15 Condition: New Fabric/Material: 7075-T6 forged aluminum Attachment/Mount Type: Picatinny Gun Type: Rifle Gun Make: Aero Precision, AR Platform Included Accessories: Standard Barrel Material: 4150 Chrome Moly Vanadium Gas Block Journal Size-Length: .750 in Bolt Carrier Group Included: No Charging Handle Included: No Weight: 48.5 oz Features of Aero Precision M4E1 AR-15 5.56 Mid Barrel Complete Upper Receiver with Flash Hider: Forged from 7075 T6 aluminum. Precision machined to M4E1 specs. M4 feedramps. Matte black hard coat anodized Mil 8625 Type 3 Class 2. Laser engraved T-marks (Anodized only). Comes assembled, with port door and forward assist installed. Handguard mounting platform is forged into the receiver. Works with Aero Precision handguards but also fits most BAR-system handguards. Features of Gen 2 Enhanced Handguard: 1pc free float design. Built in anti-rotation tabs. Scalloped rails. Continuous top rail. 1.78" inside diameter fits most muzzle devices and 1.5" suppressors. Compatible with low profile gas blocks. Quick disconnect sling socket at the 3, 6 and 9 o'clock positions. Additional milling along flats to aid with gripping and add visual appeal. New profile for the continuous picatinny top rail. Features of 16in 5.56 Mid-Length Barrel: 5.56 Nato Midlength, 1/7 twist, 4150 CrMoV, QPQ, gas port drilled. .750 gas block journal. Midlength gas system, .0785 gas port. M4 Feed Ramp Extension. HP and MPI tested. Standard A2 flash hider. Package Contents: Aero Precision M4E1 AR-15 16in 5.56 Mid Barrel Complete Upper Receiver with Flash Hider Enhanced Handguard 5.56 Mid-Length CMV Barrel Low Profile Gas Block and Mid Length Gas Tube Barrel nut and wrench